Re: [PATCH v2] dm crypt: fix deadlock when algo returns -EBUSY

[Mike Snitzer <snitzer@redhat.com>]

On Fri, Apr 10 2015 at  1:56pm -0400,
Ben Collins <ben.c@servergy.com> wrote:

> 
> > On Apr 10, 2015, at 11:11 AM, Mike Snitzer <snitzer@redhat.com> wrote:
> > 
> > On Tue, Apr 07 2015 at  1:10pm -0400,
> > Ben Collins <ben.c@servergy.com> wrote:
> > 
> >> 
> >>> On Apr 7, 2015, at 11:28 AM, Mike Snitzer <snitzer@redhat.com> wrote:
> >>> 
> >>> On Tue, Apr 07 2015 at 11:55P -0400,
> >>> Mike Snitzer <snitzer@redhat.com> wrote:
> >>> 
> >>>> It looks like you're _always_ using the completion regardless of whether
> >>>> crypt_convert() will be waiting (e.g. even if error is 0).
> >>>> 
> >>>> I can see this "working" but it seems less than ideal.  Would it be
> >>>> better to record the need to use the completion in ctx and then
> >>>> conditionally call complete()?
> >>> 
> >>> Actually, how about using !completion_done() before calling complete()?
> >>> If you think this would be OK, any chance you could re-test with this?
> >> 
> >> I'll be able to test it before Friday (out of town). Thanks
> > 
> > Hi Ben,
> > 
> > I'm still waiting for test feedback from you on v2.  Fairly certain
> > you'll have the same results but I'd like to be certain before pushing
> > this upstream.
> 
> As expected, this patch works as well as what I had originally done.
> Thanks for reviewing it.

OK, thanks.  I've staged the change in linux-next, with a slightly
revised header, see:
https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=for-next&id=223c1aa8360a386